1. Field of the Invention
The invention relates to systems for testing and diagnostics of semiconductor wafers and integrated circuits.
2. Discussion of Related Art
It is well known in the art to use various analysis tools to test and debug integrated circuits (IC) during the design, development, and manufacturing phases. Various tools are used to check the operating speed of the devices on the IC, to characterize its response to various inputs, and to investigate areas susceptible to failure. Many of these devices use light, either reflected or omitted from the IC to perform the analysis.
Since various testing equipment have various requirements, it is conventional in the prior art to build each testing apparatus as a separate tool/platform. This increases the cost of each tool, requires more floor space to house all the needed tools, and slows the testing, as the IC needs to be moved from tool to tool. Additionally, each tool requires different adapter in order to place the IC on its specially designed IC holder.
Examples of such prior art stand-alone system include diagnostic systems for performing laser probing of changing electric fields and free carrier distributions inside integrated circuits; emission systems for performing static emission analysis; systems for performing thermal mapping of IC's; systems for performing picosecond imaging circuit analysis (PICA); systems for performing measurements of resistive shorts using laser scanning techniques. However, users often need to perform a number of analyses on a particular packaged part or wafer, so they need to have all of the stand-alone tools at their disposal and need to move the IC from tool to tool to perform these various tests.
For example, a user might look at a device using static emission to find sites on the device which are drawing excessive power. Once the sites are located the user might wish to use a separate time-resolved photon emission tool to probe dynamic activity in a net near the location of the excessive emission. However, Fixturing the IC in each of the diagnostic machines typically takes an hour or more. Moreover, in each individual tool electrical connections, cooling apparatus for the device under test, etc. are provided independently, thereby increasing the cost of each tool. Furthermore, once the IC has been mounted on the second tool, the area of interest on the IC needs to be identified and located again. Thus, performing more than one type of testing on an IC is a cumbersome operation.
A user may also switch among several tools as he performs a variety of measurements while trying to discover the root cause of the problem. However, settling time for the device, if it requires cooling before moving it to the next tool, can take several hours. In most cases the tester is required during device setup. Tester time is expensive and often difficult to obtain.
Therefore, there is a need in the industry for a simplified process for enabling more than one type of testing on an IC without transferring the IC among various testers.